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How does the iphone 4s camera work?

  1. Oct 20, 2011 #1
    Many people use the iphone nowadays. But I wonder if they know exactly how it works?
    I found a description of the technologically advanced iphone 4s camera features, and I curious as to how it works. The lines in red are what I found from the apple website.

    The iPhone 4S camera gives you 8 megapixels — that’s 60 percent more pixels than the camera on iPhone 4. They’re engineered with a higher, full-well capacity to collect even more light. With more megapixels and more light, you’ll see a dramatic difference in the resolution and details of your images. So your photos look stunning everywhere you show them off — on your iPhone, your computer, or your HDTV. And they’re rendered pixel for pixel in prints as large as 8x10.

    Questions: How do you make them have a higher capacity? And why does having a higher capacity allow them to collect even more light?why do more megapixels and more light cause a diff in the resolution and details of the images? Why is it that when the images are printed they can be rendered pixel for pixel?

    Great photography isn’t just about megapixels — it’s about light, too. The all-new, advanced optics in this camera work together to make sure whatever light you have gives you the best image possible. The custom lens uses five precision elements to shape incoming light, which makes the entire image sharper. The larger f/2.4 aperture lets in more light, so photos look brighter and better. And the advanced hybrid infrared filter keeps out harmful IR light, so you’ll see more accurate and uniform colors.

    Questions: How do the advanced optics in the camera work together to ensure whatever light one had gives the best image possible? What are the five precision elements that the custom lens has? (ok, perhaps only the producers know this secret) what is a larger f/2.4 aperture? Why does it let in more light? What is an advanced hybrid infrared filter? Why does keeping out infrared light allow us to see more accurate and uniform colors?

    Pull out your iPhone in moonlight, candlelight, or under little white lights. Or shoot in bright light. Like at the beach. iPhone captures low-light and lots-of-light moods beautifully. So darks aren’t too dark and lights aren’t too light. Even action shots are less blurry. The next-generation backside illumination sensor is engineered with increased sensitivity and a shorter exposure time to achieve the same scene brightness — colors are less saturated and you’ll see more details. And the LED flash automatically kicks in when it’s needed (but you can always turn it off).

    Questions: how does the camera ensure darks are not too dark and lights are not too light? How does it make action shots less blurry? What is a next-generation backside illumination sensor? How do you engineer it with increased sensitivity and shorter exposure time? Why does increasing the sensitivity and shortening the exposure time allow the sensor to achieve the same scene brightness? What is same scene brightness? Why are the colors less saturated and allow us to see more details? How does the led flash kick in automatically when its needed?

    The A5 chip is designed with an image signal processor that’s just as good as the ones found in DSLR cameras. It’s how you can tap to focus and control exposure. And it’s the power behind zero shutter lag. The image signal processor makes the iPhone 4S camera faster, so you’ll catch all the action as it happens. The camera also uses advanced algorithms in iOS 5 for even more color accuracy, better white balance, and greater dynamic range. When you see your photos, you’ll see exactly what that means.

    Questions: what is an image signal processor?how does the a5 chip allow us to tap to focus and control exposure? How does it allow zero shutter lag? What are advanced algorithms? How do they allow even more color accuracy, better whute balance and greater dynamic range? What is greater dynamic range?

    With new face detection, this camera is smart enough to know whether you’re taking a portrait or a group shot. It focuses on the most prominent face in the frame and balances exposure across up to 10 faces. So you’ll definitely catch smiles. And maybe even a smirk or two.

    Questions: how does the camera detect a portrait or group shot? How does it focus on the most prominent face in the frame and balance the exposure?


    Tap HDR and take a photo. iPhone 4S captures three photos from that one shot, each with a different exposure level. Then it layers the shots together to create a single photo that combines the best parts of each shot. The wide range of light is more accurate in an HDR photo. And iPhone saves both the original and the HDR photo in your Camera Roll. You can clearly see the difference.


    Questions: How does the camera capture three photos from one shot? How does the camera capture them with diff exposure level? How does the camera layer the shots together to create a single photo that combines the best parts of each shot?

    ps: i know i'm a bit obesssed, you may think i'm weird but i just want to know how things work.
     
  2. jcsd
  3. Oct 20, 2011 #2

    Borek

    User Avatar

    Staff: Mentor

    See this thread:

    https://www.physicsforums.com/showthread.php?t=464937

    Just because the camera is built into iPhone doesn't mean it is different from other digital cameras, physics behind is identical.

    I am closing this topic, before it attracts spammers. And you can be sure it will :grumpy:
     
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